JPS642484B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a porous rubber sheet (screen) used for sieving crushed stone and ore, and in particular, to a method for preventing the occurrence of The present invention relates to a method for manufacturing a porous rubber sheet (screen) that can efficiently remove burrs that adhere to products that cannot be used.

(Prior art) As a conventional technology, a raw raw rubber sheet is pressed between a die provided with a large number of hole-forming protrusions and a flat surface of a molding press pressure plate to produce a porous rubber sheet (porous rubber screen). By interposing a release sheet such as a cloth sheet or a vulcanized rubber sheet between the material raw rubber sheet and the pressure plate, and peeling off the cloth sheet or vulcanized rubber sheet after vulcanization, There is a method of obtaining a porous rubber screen without burrs (for example, the inventions described in Japanese Patent Publication No. 49-34474 and Japanese Patent Publication No. 52-10478).

(Problems to be Solved by the Invention) However, the above-mentioned prior art has the following problems. In other words, release sheets such as cloth sheets and vulcanized rubber sheets have too much elasticity, so wrinkles and unevenness tend to occur on the surface of the final product screen, resulting in uneven thickness, which makes it difficult to support the screen when actually using the product. Point contact occurs at the part that comes into contact with the frame, which causes phenomena such as abnormal wear and cutting. In addition, if the thickness of the burr generated between the release sheet and the top surface of the hole-forming protrusion is thin (0.1 to 0.2 mm), the binding force between the release sheet and the burr exceeds the strength of the burr itself, so the peeling The burr is relatively easy to remove when peeling the sheet, but if the burr becomes partially thick due to the weight and shape of the product, it becomes difficult to remove the burr, and the burr may remain on the edge of the hole of the screen product. Many of them are troublesome to remove. These burrs are usually
The burrs are removed by buffing, but since rubber is an elastic material, depending on the polishing direction, some parts of the burr can be cut and some parts cannot. In other words, the burr on the side where the burr becomes the main body is cut, but the burr cannot be cut in the direction from the main body to the burr. Furthermore, if a rubber material that is easily buffed is used, the durability of the screen itself will be reduced. Furthermore, according to the method of punching out burrs using a punch, if the tip of the punch does not hit the burr surface at right angles and accurately, a small amount of burr will remain in the shape of a flange at the edge of the hole, and if there are many holes, the punch It is difficult to set it accurately in the hole,
If the punch itself is made smaller, it still has the disadvantage of leaving a flange-shaped burr on the edge of the hole. Removing these burrs was a very laborious and time-consuming task.

(Means for solving the above-mentioned problems) The present invention was invented in view of the above-mentioned problems, and is intended to unevenly eliminate burrs that adhere to the product and generate when manufacturing this type of porous rubber screen. The purpose of the present invention is to provide a method for manufacturing a porous rubber screen that can be removed uniformly without any scratches.

The configuration of the present invention will be explained below.

That is, the gist of the present invention is as follows:
In a method of manufacturing a porous rubber sheet by sandwiching a raw raw rubber sheet between a frame provided with a large number of hole-forming projections and a flat surface of a pressurizing/heating plate, there is a gap between the raw raw rubber sheet and the pressurizing/heating plate. , a porous rubber characterized by inserting cardboard and press-molding a material raw rubber sheet so that the cardboard is completely adhered to the rubber surface, and after removal, the cardboard and the rubber adhering to it are removed by buffing. This is a sheet manufacturing method.

Next, one embodiment of the present invention will be described based on the accompanying drawings.

Figure 1 is a cross-sectional view of a porous rubber sheet immediately before production, where 1 is a press heating plate, 2 is a press surface plate 1
3 is a hole-forming projection provided on the frame 2, and 5 is movable up and down so as to approach or separate a flat surface parallel to the top 8 of the hole-forming projection 3. The installed pressure heating plate is shown.

In these devices, the raw rubber sheet 4 is placed on the top 8 of the hole-forming projection 3 of the frame 2, and then the cardboard 6 is placed on top of this.

Next, as shown in FIG. 2, by lowering the pressurizing and heating plate 5, the raw rubber sheet 4 is pressed between it and the frame 2 through the cardboard 6. In this way, the rubber material 4' (same material as the raw rubber sheet 4) sandwiched and pressed between the pressure heating plate 5 and the frame 2 fills the void 7 existing between the hole-forming protrusions 3, and the rubber in the void The burr 9 formed between the upper surface and the top 8 of the hole-forming projection 3 and the cardboard 6 is completely adhered to the cardboard 6. At this time, the burr 9 becomes extremely thin due to the pressing force of the cardboard, which has both appropriate rigidity and elasticity. In addition,
It is not necessary to use only one piece of cardboard, but it is effective to use two or more sheets, taking into account various conditions such as the degree of pressure of the pressure heating plate, vulcanization conditions, and the thickness of the product to be manufactured.

Next, after unloading and depressurizing the pressurizing and heating plate 5, the frame body 2 is removed, and as shown in FIG. However, by bubbling the screen to a position close to line B-B, a porous rubber screen from which burrs are removed can be obtained.

(Example) In the method for manufacturing the porous rubber sheet of the present invention described above, cardboard with a thickness of 1 mm was used as the cardboard, and rubber with particularly good abrasion resistance was used as the raw rubber material.

The surface pressure of the pressure heating plate is 30Kg/ ^cm2 , the hole size is 25mm square,
A porous rubber screen with a width of 1500 mm and a length of 600 mm was manufactured.

The cardboard was completely adhered to the surface of the obtained porous rubber body, and the desired burr-free porous rubber screen product was obtained by uniformly buffing the cardboard and the burrs attached thereto.

(Function and effect) The method for manufacturing the porous rubber sheet of the present invention configured as described above involves interposing cardboard between the pressure heating plate and the raw raw rubber sheet, and by pressure forming the cardboard to the surface of the product rubber sheet. Because the cardboard has a suitable rigidity and elasticity, the burrs generated between the cardboard and the top of the hole-forming protrusion become a thinner layer due to the pressing force caused by the appropriate rigidity and elasticity of the cardboard. Since it adheres completely, by using cardboard as a guide and buffing it slightly thicker than the thickness of the cardboard, it is possible to remove the cardboard and the burrs attached to it at the same time, making the buffing process extremely easy.

In addition, the thick paper such as cardboard used in the present invention has extremely low thermal shrinkage and good dimensional stability compared to rubber etc., so it is not affected by the heat during pressure vulcanization and wrinkles etc. Since no generation occurs, the surface near the edge of the porous rubber sheet used as a product does not become uneven. Moreover, since cardboard does not have rubber elasticity and deforms plastically, it contracts due to pressure at the point where it comes into contact with the hole-forming protrusion during pressure molding, but does not contract at the hole, so it is locked at the hole-forming protrusion. The cardboard will not move or shift on the hole forming jig. Therefore, the flat surface shape of the cardboard is directly reflected on the surface of the porous rubber sheet as a product, resulting in a porous rubber sheet with a flat surface shape.

In particular, due to fluctuations in the pressing force of the pressure heating plate and other manufacturing conditions, even if a single piece of cardboard cannot sufficiently prevent the occurrence of wrinkles, it is possible to prevent wrinkles by using multiple sheets of cardboard, such as two or three sheets. It is more effective as it can completely prevent the appearance of wrinkles.

Furthermore, when buffing cardboard, cardboard has appropriate rigidity and elasticity, so unlike rubber, there is no escape due to buffing pressure, so it is possible to uniformly buff the entire surface of the product. Instead, as mentioned above, the burr is extremely thin and completely adheres to the back of the cardboard, so by buffing it using the cardboard as a guide, the burr can be completely removed.

As described above, the product porous rubber sheet obtained by the present invention does not have burrs remaining in the pores, so that the sieving efficiency is improved. Moreover, since the surface of the edge of the product is flat with no irregularities or wrinkles, it makes surface contact with the screen support frame rather than point contact, which can lead to problems such as abnormal wear and cutting, and reduce the durability of use. improves.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram when the present invention is implemented (immediately before manufacturing a porous rubber sheet), Fig. 2 is an explanatory diagram when the present invention is also implemented and pressurized with a pressure heating plate, and Fig. 3 is an explanatory diagram when the present invention is implemented (just before manufacturing a porous rubber sheet). FIG. 2 is an enlarged sectional view of a main part, and FIG. 4 is a sectional view of a semi-finished product obtained by removing the frame after pressure forming. DESCRIPTION OF SYMBOLS 1...Press heating plate, 2...Frame body, 3...Hole forming projection, 4...Material raw rubber sheet, 4'...Rubber material,
5... Pressure heating plate, 6... Cardboard, 7... Gap, 8...
...Top part, 9...Flash, 10...Lower mold, B-B line...Buffing surface.

Claims (1)

[Claims] 1. In a method of producing a porous rubber sheet by sandwiching a raw rubber sheet between a frame provided with a large number of hole-forming projections and a flat surface of a pressurizing and heating plate, the gap between the raw raw rubber sheet and the pressurizing and heating plate is The method is characterized in that cardboard is inserted and the material raw rubber sheet is pressure-molded to completely adhere the cardboard to the rubber surface, and after the pressure is removed, the cardboard and the rubber adhering to it are removed by buffing. A method for manufacturing a burr-free porous rubber sheet.